U.S. Pat. No. 3,764,623 discloses Herbicidal Dinitro-1,3-Phenylenediamine Compounds. U.S. Pat. No. 4,818,275 discloses Herbicidal Aryl Triazolinones.
The use of herbicides for crabgrass control in turf is well known. There are two types of herbicide applications for this purpose, pre-emergence herbicides that prevent crabgrass seeds from germinating or emerging and post-emergence herbicides that control emerged and actively growing plants.
Pre-emergence turf herbicides are generally more effective, but must be applied early in the season before crabgrass seeds germinate. In order to provide season-long control most pre-emergent herbicides need to be re-applied six to eight weeks after the initial application. A population of crabgrass, either over an entire site or in localized areas of a site, cannot be confirmed so early in the season, the time and expense of treating turf with pre-emergence applications of herbicides may not be needed.
Post-emergence turf herbicides are used to control crabgrass after germination and emergence from the soil. The benefit of using a post-emergence turf herbicide for crabgrass control is that it is used only if and where crabgrass is present. Some of the most common post-emergence turf herbicides must be reapplied several times, for example, organic arsenicals which include MSMA (monosodium methanearsonate), and DSMA (disodium methanearsonate); and others injure or turn turf grasses yellow after application, for example, fenoxaprop ((+/−)-ethyl 2-[4[(6-chloro-2-benzoxaolyl)oxy]phenoxy}propanoate) and quinclorac(3,7-dichloro-8-quinolinecarboxylic acid).
It would be most beneficial to provide a post-emergence turf herbicide that controlled crabgrass in one application and without injury to turf grasses.